Ecological plasticity and resistance of soybean varieties in agroclimatic conditions of the Kaluga region

The article presents the results of agroecological studies of soybean varieties and their adaptive potential in the Kaluga region in the Spas-Demensky district in 2016-2019. To determine the level of environmental plasticity and stability a methodology developed by S.A. Eberhart and W.A. Russell and adapted by V.A. Zykov was used. To assess stress tolerance and average yield under various conditions, the A.A. Rossille and J. Hamblin equation was applied. In addition, the environmental conditions index (Ij) was determined, and plasticity was assessed using the linear regression coefficient (bi). This made it possible to identify the degree of ecological stability of the varieties, as well as their ability to withstand stress factors and adapt to changing conditions. Favorable conditions for cultivating varieties were in 2016, the index of environmental conditions i j had positive values – 0.27. The varieties Pripyat (b i =1.82), Georgiya (b i =1.65), Okskaya (b i = 1.43), and Volma (b i = 1.27) showed high plasticity. The best grades in terms of ecological stability (σd 2 ) are Svetaya (0.0008) and Pripyat (0.0002). In the agro-climatic conditions of the Kaluga region, Mageva, Svetaya, and Kasatka varieties showed increased resistance to stress factors (-0.27). Pripyat (2.1) and Okskaya (2.0) varieties have higher genetic flexibility. The Pripyat variety has the best performance in terms of yield, environmental plasticity, stability, and genetic flexibility.